Morpho-phenetical study of high yielding tossa jute variety BJRI Tossa Pat 7 (MG-1) for bast fibre yield and qualities.

BACKGROUND AND AIM OF THE STUDY: Tossa jute (Corchorus olitorius) is a natural fibre crop produces good quality fiber having great demand for industrial uses. High yielding tossa jute variety is very important in Bangladesh. MATERIALS AND METHODS: Bangladesh Jute Research Institute (BJRI) has developed a new tossa jute variety (BJRI Tossa Pat 7) through pure line selection (PLS) from another pre-released variety named OM-1 during 2017. The new variety was evaluated for fiber yield and attributing phonological traits through comparing with another pre-released variety named BJRI Tossa Pat 5 (O-795) in RCB design at six locations during 2015-2018. RESULTS: Distinct morphological traits i.e. ovate lanceolate glossy leaves; full green plant were found in MG-1 and stem & stipule red; ovate lanceolate leaves in O-795. MG-1 showed higher fiber yield (3.39-3.40 t ha-1) where, O-795 showed 3.10-3.22 t ha-1 as means of their maximum performances for three years at both farmers' plots and research fields. MG-1 gave higher plant height, base diameter, fiber yield than O-795 at both research stations and farmers' fields. Even after sowing at 10-15 March, MG-1 gave late flowering; lower leaf size, leaf angle, green leaf biomass and node number; maximum inter-nodal length, bark diameter, bark thickness and fiber bundle cells; and finally golden bright quality fiber than O-795. If both varieties were sown at 2nd to 3rd week of March, and harvested at 110 days old, MG-1 gave 5-7% higher fiber yield than O-795. CONCLUSION: Undoubtedly, MG-1 is a good tossa jute variety for its fiber yield and quality than pre-released varieties. RECOMMENDATION: MG-1 having good fiber yield would be used for commercial cultivation by the farmers to contribute to the national economy.

Comparative performance analysis of 2D and 3D gamma metrics for patient specific QA in VMAT using Octavius 4D with 2D-Array 1500.

INTRODUCTION: Gamma pass percentage (GPP) is the predominant metric used for Patient Specific Quality Assurance (PSQA) in radiation therapy. The dimensionality of the measurement geometry in PSQA has evolved from 2D planar to 3D planar, and presently to state-of-the-art 3D volumetric geometry. We aim to critically examine the performance of the three-dimensional gammas vis-à-vis the older gamma metrics of lower dimensionality to determine their mutual fungibility in PSQA, using clinically approved Volumetric Arc Therapy (VMAT) plans. METHODS AND MATERIALS: Gamma pass percentages derived from PSQA for VMAT plans using Octavius 4D phantom with 2D-Array 1500 and its proprietary software were recorded. 2D planar, 3D planar, and 3D volumetric gamma pass percentages were retrospectively extracted for multiple treatment plans at three sites, using three acceptance limits, and for two modes of normalization. The differences in mean pass percentages, and the pairwise correlation between geometries were calculated within limits of statistical significance. RESULTS: A significant increase in mean pass rates was observed from 2D planar to 3D planar geometries. The difference was less pronounced from 3D planar to 3D volumetric. 2D planar v/s 3D planar showed a significant degree of correlation among themselves, which was not seen against most of the 3D volumetric pass rates. CONCLUSION: The mean gamma pass rates show conclusive evidence of the benefits of shifting from 2D planar to higher dimensions measurement geometries, but the benefits of using 3D volumetric compared to 3D planar is not always unequivocal. The correlations show mixed results regarding the interdependence of pass percentages at different geometries.

Effect of Heating on Compositional Characteristics and Oxidative Stability of Crude and Refined Rice Bran Oil.

The compositional characteristics and oxidative stability of rice bran oil were determined by observing the formation of oxidative products and alteration in chemical composition of oils during microwave or oven heating. The values of oxidative indicators such as free acidity, peroxide, p-anisidine, total oxidation, thiobarbituric acid and color values, increased faster in refined oils compared to crude ones during heating. In gas chromatography analysis, the percentages of total saturated, monounsaturated and polyunsaturated fatty acids in the studied oils such as lab extracted crude rice bran oil, lab extracted and refined rice bran oil, crude rice bran oil from commercial mill and refined rice bran oil from commercial mill were: 23.07 to 23.56, 41.15 to 42.38 and 34.38 to 35.88, respectively. The heating caused the reduction of polyunsaturated fatty acids content with increasing saturated fatty acids content, and these changes were greater in refined rice bran oil indicating extensive lipid oxidation occurred in refined oil. The change in triacylglycerol species content as determined by High-performance liquid chromatography, was lower in crude oil; the higher stability of these species in crude oil could have contribution to reduce oxidation. During thermal treatment, the generation of hydroperoxides, their degradation and formation of secondary oxidative products evaluated by Fourier-transform infrared spectroscopy, were lower in crude oils. However, the rate of formation of oxidative products in lab prepared samples was lower compared to that in the samples collected from commercial mill. Under extreme thermal condition, the order of oxidative stability: lab extracted crude rice bran oil > crude rice bran oil from commercial mill>lab extracted and refined rice bran oil > refined rice bran oil from commercial mill. The present results will be useful to oil seed processing mills in refining of rice bran oil for economic feasibility and better marketability.